Venetian blind mechanism



A1181 6, 1963 E. E. RANDMARK 3,100,013

VENETIAN BLIND MECHANISM Filed. April 4, 1961 INVEN TOR. ERIC E. RANDMARK ATTORNEYS United States Patent 3,100,013 VENETIAN BLIND MECHANISM Eric E. Randmark, Stockholm, Sweden, assignor to Victor J. Randmark, Rossford, Ohio Filed Apr. 4, 1961, Ser. No. 100,575 7 Claims. (Cl. 160-168) This invention relates to blinds of the type comprising a plurality of spaced substantially parallel slats which can be tilted and can be displaced to alter their spacing and particularly to a novel combination of elements for such tilting and displacing mechanism.

A primary object of the invention is to improve slat type blinds.

Another object is to reduce the expense of construction, installation and maintenance of slat type blinds.

A third object is to increase the flexibility of application of slat type blinds.

A further object is to enhance the operation of slat type blinds particularly [by avoiding malfunctions and misadjustments due to improper operation.

A primary feature of this invent-ion resides in the utilization of a flexible band which can be reciprocated along its length and has a portion turned back upon itself so that reciprocation raises the side elements of the slat support on one face of the blind structure and lowers the side elements on the other face thereby altering the angle of inclination of the slats and the area exposed through the blinds. Another feature resides in the incorporation of mechanical limits on the degree of travel for the reciprocating band to avoid misadjustrnent or dam-age to the slat supports during the tilting of the slats. A further feature involves utilization of flexible tubes as guides for the control cords of a blind to enable the point at which controlling tension is imposed on the cords to be displaced from the head bar of the blind as where the blind is spaced between an inner and outer window and the cord guides extend past the inner window to the interior of the structure. An additional feature involves the mount-ing of cord guides on a swiveled support adapted to be turned whereby access is afforded to the cords from either the face of the blind or the end of the blind.

The above and additional features of this invention will be more fully appreciated from the following detailed description when read with reference to the accompanying drawings in which:

FIG. I is a perspective view of a portion of a blind, elements thereof being broken away to reveal details; and

FIG. II is a plan view of the guide adjusting means showing its application in one installation for which the blind is particularly adapted.

As illustrated in FIG. I the blind consists of a plu rality of slats 11, only two of which are shown. It is suspended from a head bar 12 formed as a trough having a bottom 13 and upturned sides or flanges 14 and 15. Support for the blind slats is afforded by a flexible ladderlike structure which may be of cord or tape. In the eX- ample the slat support structure is composed of side elements 16 and 17 extending vertically along the front and rear faces respectively of the slats and connected by a plurality of vertically spaced cross supports 18 upon which the slats 11 rest. The slats are tilted by adjustment of two or more of these support structures by altering the vertical displacement of the side elements 16 and 17. The slats are raised and lowered in a generally conventional manner by means of lifting cords 19 which pass through apertures 21 which are aligned in the several slats such that the cords can be drawn upward to raise the lowermost slat and successively pick up the slats above.

3,100,013 Patented Aug. 6, 1963 Head bar 12 contains the control mechanism for the blind. The tilting mechanism comprises a flexible tape or band 22 which can be reciprocated parallel to the axis of the head bar by the application of tension to the tilting cords 23 and 24 connected thereto. Side elements 16 and 17 are connected to the tilting tape 22 by any suitable means such as the tabs 25 so that reciprocation of the tape 22 effects vertical displacement of those elements by drawing one set of the elements partially into the head bar while extending the other set of elements from the bar.

In onder to lower the foremost edge of the slats 1'1 and raise the rearmost edge, the side elements 16 should be lowered and the side elements 17 raised. This is done by moving the turning cord 23 downward to draw the front portion 26 of tape 22 to the left and the rear portion v26 to the right so that the cords 16 pass through the anti friction bushings or guide members 27 in the bottom 13 of the head bar 12 while the cords 17 are drawn through the anti-friction bushings or guide members 28 in bottom 13 upward and into the head bar.

It will be noted that with the above arrangement twisting of the flexible band 22 is avoided by the arcuate slot 29 in the end block 31 secured within the trough as by means of the screw 32. The band 22 can advantageously be composed of metal such as steel so that it can be slid in the slot 29 while its major faces are held vertical and the ends issuing therefrom form first and second portions 26 and 26 which extend along the head bar and are essentially parallel to the longitudinal axis of the bar. This slot closely fits the turning band 22 and carries it around a vertical cylindrical surface providing a gentle curve of sufiicient radius to avoid stressing the material of the band beyond its elastic limit whereby the desired displacement of the band can be readily attained by applying tension to one side or the other and the band is positively guided by a means which is inexpensive in first cost and involves no moving parts requiring maintenance.

In the construction discussed, excessive longitudinal motion of the band 22 can result in the lifting of the slats in a manner in which the mechanism is not intended to function and can draw the uppermost slat against the underface of the head bar. This undesirable result is avoided by the use of the limits or stops 33 in the form of tabs projecting outwardly from the walls 14 and 15 of the channel forming head bar 12. Stops 33 are arranged to be engaged by the shoulders 30 formed at the band ends when the band has been displaced sufiiciently to effect the maximum tilting of the slats. These tabs also function as guides for the turning cords 23 and 24 whereby the need for rotatably mounted guide pulleys to confine the range of movement of the cords is avoided. Forces can be imposed on the end portions 26 and 25 of the tapes to which the side elements 16 and 17 of the slat supports are connected which tend to twist the tape. The confining slot 29 opposes these twisting forces at one end of each tape portion and the tensioning means by which the tapes are reciprocated tend to overcome twisting forces at the other end. Two lengths of cord connected at spaced positions across the width of the tape and confined to vertically spaced cord guides retain the tape in its vertical orientation across its width.

Cord 23 is led into the head bar through a flexible tubular member which maybe made up of a closely coiled metallic spring 34 mounted on a flange 35 secured to the channel 12. Cord 23 is guided through the open center portion of the flexible tube 34, through an aperture in the flange 35 registering with the bore of tube 34, and thence around the guide pin 36 mounted on the bottom 13 of the channel. Within the head bar the cord 23 passes the guide pin 36, is led through an aperture 37 in the stop 33 and to a pulley 38 journalled on one end 26 of the band 22.

point the cords are secured. double length of cord fixed in position by means of the guiding apertures of the limit tabs 33 confines the discentrally located on the width of the head bar.

the tilting cords by using a double purchase through the return of the cords from the pulleys 38 and 41 to some fixed point such as the base of the pins 36 and 39 at which It will be noted that the placement of the free ends of the turning band 22 whereby any twisting effect of the forces imposed on the band through the slat support side elements 16 and .17 is opposed.

Lifting cords 19 are similarly made accessible for control by training them from the bottom of the blind slats through registering apertures 21 in the several superimposed slats into the channel forming head bar 12 through anti-friction bushings 42, thence to the pin 43 fixed on the bottom of the head bar, past that pin and struction is provided with a base having a major face 45 parallel to the bottom 13 of channel 12 and seated thereagainst. The flange 35 is integral with and turned upward from this major face 45. As best seen in FIG. II

. face 45 is cut away to provide a clearance for the guide pins 36 and 39 and is generally triangular in form ter minating in the vicinity of the point about which the plate and flange 35 are pivoted. This pivot point can advantageously be integral With the guide pin 43 and is Thus, when it is desired to issue the control cords from the end of. the blind construction, the plate 35 is rotated about pin 43 to position the plate 35 perpendicular to the face of the blind and the cord guides or tubes 34 and 44 parallel to the blind face.

:The paths along which the control cords are guided when they issue from either the end or face of the blind are established by the relative positions of the guide tubes .34 and 44, the guide pins 36, 3'9 and 43, and the guide apertures in limit tabs 33. diagonal of the square face at the end'of bottom 13 and Pin 43 is located on the is aligned with tthe center of the sides of that square so that cord 19 is guided (along the center of the head bar for :both orientations of flange section 35. Pins 36 and 39 are also effective for either orientation of flange section 35 since they also are located generally on the diagonal and are aligned along the length of the head bar with the apertures in tabs 33. The tube guide in flange section 35 are similarly aligned along the head bar when the flange is perpendicular to the face of the blind so that tube 44 essentially is centered while tubes 34 are aligned generally with the pins 36 and 39 along the tube length. With the flange section 3-5 parallel to the length of the head bar, the

- alignment between the tubes and pins is maintained and each cord is carried through a 90 turn around its guide Que utilization of the present blind construction which is particularly effective is between double windows represented by the wood frames 46 and 47 of FIG. II. In such applications the guide tubes 34 and 44 are extended .lthnough apertures in the frame 47 thereby avoiding abrasubstantially to carry its cord through a circuitous path 4 Without adverse effects as. by displacing the aperture 48 in frame 47 through which tube 34 passes from a position registering with the aperture, 49 in flange 35 in which tube 34 is secured.

While the terms baud" and tape have been employed as synonyms in this specification and the appended claims for the element 22, it is to be appreciated that the physical characteristics of that element are such that it is flexible in the dimension normal to its major surface and relatively rigid in its dimensions lying in the major sunfiace. Spring steel is one example of a material offering these characteristics and thereby precluding any twisting of the tape 101 band 22 which might foul the cords for tilting the blind. However, other materials such a bands of other metals or plastic might also be employed and the band 22 might even the composite, for example, comprising spring steel in the region carried around the arouate slot 29 in end block 31 and less expensive metal or plastic in the lengths which parallel the head bar side walls 14 and 15. The rigidity of the band 22 can be sup plemented where necessitated by the forces transmitted through cords 16 and 17 by providing guides 51 generally aligned with the grommet-s 28 and confining the tape to a longitudinal sliding motion against the head bar side walls 14 and 1 5.

While this disclosure has not included any means (for locking the lifting cord-s .1 9 at intermediate positions whereby the blind can be partially raised, it is to be appreciated that such locking mean can be incorporated in the structure, such means being well known and therefore not requiring illustration here.

The above described features of the invention can be used either singly or in combination. Therefore, it is to be appreciated that many substitutions of elements and modifications of the above disclosed structure can be made without departing from the spirit and scope of this invention. Accordingly, this disclosure is to be read as illustrative of the invention and not in a limiting sense.

I claim:

1. A blind comprising a plurality of substantially horizontal slats, a substantially horizontal head bar, a pair of slat supports suspended below said head bar, a first and a second flexible side element for each support extending generally vertically along opposite faces of said blind, a plurality of vertically spaced cross supports for each slat support extending [between said side elements to support said slats, a flexible tape having a substantially greater width than thickness, a body secured to said head bar adjacent one end thereol= having a slot which is semicircular about a vertical axis and of a vertical depth to accommodate the width of said tape, said tape being trained through said slot and having first and second end portions on opposite sides of said slot which extend along sazidhead bar and are essentially parallel to its longitudinal axis, a connection between each of said first side elements and said first end portion of the tape and between each of said second side elements and said second end portion of the tape, a guide :for each side element intermediate said connection and said cross supports and secured to said head bar, a cord connected to each of said end portions of said tape, a stop fior engagement with each end portion of said tape to limit its longitudinal movement, a cord guide on each of said stops, a member pivoted on said head bar around a substantially vertical pivot ladjacenrt rthe end of said bar spaced from said body, a ventical flange on said member adjacent an edge of said head bar, and a plurality of cord guides on said flange, said cords extending from said guides on said stops to said guides on said flange.

2. A blind comprising a plurality of substantially horizontal slats, a substantially horizontal head bar having a first and a second end, a pair of slat supports suspended below said head bar, a first and a second flexible side element for each support extending generally vertically along opposite faces of said blind, a plurality of vertically spaced cross supports for each slat support extending between said side elements to support said slats, a flexible tape having a substantially greater width than thickness, a body secured to said head bar adjacent said first end thereof having a right-circular cylindrical surface over the semicircular region facing said first end and extending about a vertical axis, said surface having a vertical dimension of substantially the width of said tape, said tape being trained over said surface and contacting said surface over a substantial portion of its width to maintain its plane generally normal to said head bar, said tape having first and second end portions on opposite sides of said surface which extend along said head bar and are essentially parallel to its longitudinal axis, a connection between each of said first side elements and said first end portion of the tape and between each of said second side elements and said second end portion of the tape, means spaced along said head bar from said surface engaging the face of said tape at points spaced across said tape width, said means being coupled to said head bar to maintain said spaced points in a plane generally normal to said head bar whereby said tape is maintained generally normal to said head bar in a region spaced from said surface, a guide for each side element intermediate said connection and said cross supports and secured to said head bar, and means to apply tension to the ends of said tape to displace it longitudinally.

3. A blind comp-rising a plurality of slats, a substantially horizontal head bar of channel form, opposed, generally vertical side walls on said head bar extending longitudinally, a pair of slat supports suspended below said head bar, a first and a second flexible side element for each support extending along opposite faces of said slats, a plurality of vertically spaced cross supports for each slat support extending between said side elements to support said slats, a flexible tape within said channel form head bar having a substantially greater width than thickness, a body secured to said head bar between said side walls having a vertical cylindrical surface having a vertical dimension of at least a substantial portion of the width of said tape, said tape having first and second portions which are adjacent and are substantially parallel and a portion intermediate said first and second portions trained around said cylindrical surface and bearing upon said surface over a substantial portion of the tape width to maintain the major tape surface generally normal to said head bar, connections between the first side elements of said supports and said first portion of said tape and between the second side elements of said supports and said second portion of said tape, tape guide means engaging each of said end portions of said tape at points spaced across the width thereof in a location spaced along said head bar from said cylindrical surface, each of said guide means being coupled to said head bar and being spaced from one of said side walls a distance less than the width of said tape, said tape portions each being disposed between a side wall and a guide means to maintain their width dimensions generally vertical, a guide for each side element located between said cross supports and said connection to said tape and fixed with respect to said head bar, and means to reciprocate said tape along its length whereby said first and second side elements are displaced with respect to said guides to alter the inclination of said slats.

4. A blind according to claim 3 wherein said first and second side elements are connected to the major faces of said first and sec-0nd portions most remote from said side walls of said head bar, and said guide means for said tape are proximate to said connections of said side elements to said portions and are arranged to permit reciprocation of said portions and connections.

5. In a Venetian blind, a plurality of spaced substantially horizontal slats, a substantially horizontal head bar, carrying members suspended below said head bar each comprising two side elements and a plurality of vertically spaced cross supports extending between said side elements to support said slats, a body portion on said head bar having a semicircular slot the axis of which is vertical, a flexible tape trained around said slot and extending longitudinally of said head bar with its ends parallel and adjacent to each other, flexible means extending from each of said side elements upward through said head bar and connected to said flexible tape, a moveable member pivoted on said head bar adjacent an end of said bar and adapted for rotation about a vertical axis, a vertical flange on said moveable member, a plurality of flexible tubes secured to said flange and projecting outwardly of said head bar, and a cord connected to each end of said tape for displacing said tape along said head bar and thereby displacing said side elements Vertically to tilt said slats, said cords being trained through said tubes.

6. A blind comprising a plurality of slats, a substantially horizontal head bar, means to tilt said slats, means to adjust the separation of said slats, a member pivoted on said head bar around a substantially vertical pivot, a vertical flange on said member adjacent an edge of said head bar, a plurality of cords for operating said slat tilting and adjusting means, couplings between said cords and said tilting and adjusting means, and guides for said cords secured to said flange whereby the position of said flange about said pivot determines the location of said cords external of said blind structure.

7. In a Venetian blind including a plurality of spaced substantially parallel slats, means to reduce the spacing between said slats, means to tilt said slats, to alter the angularity of said slats, a horizontal head bar, :a sec tion pivoted on said head bar for rotation about an axis normal to said bar, a substantially perpendicular flange on said section, a plurality of cords for actuating said means, couplings between said cords and said tilting and adjusting means, and a flexible tubular guide extending outwardly of said head bar from said flange whereby said cords trained through said guide are available from the end of said blind when said flange is transverse of the blind face and from the face of said blind when the flange is parallel with the blind face.

References Cited in the file of this patent UNITED STATES PATENTS 1,611,845 Allen Dec. 21, 1926 2,572,291 Weaver Oct. 23, 1951 2,639,766 Pratt May .26, 1953 2,759,535 Berglind Aug. 21, 1 956 

1. A BLIND COMPRISING A PLURALITY OF SUBSTANTIALLY HORIZONTAL SLATS, A SUBSTANTIALLY HORIZONTAL HEAD BAR, A PAIR OF SLAT SUPPORTS SUSPENDED BELOW SAID HEAD BAR, A FIRST AND A SECOND FLEXIBLE SIDE ELEMENT FOR EACH SUPPORT EXTENDING GENERALLY VERTICALLY ALONG OPPOSITE FACES OF SAID BLIND, A PLURALITY OF VERTICALLY SPACED CROSS SUPPORTS FOR EACH SLAT SUPPORT EXTENDING BETWEEN SAID SIDE ELEMENTS TO SUPPORT SAID SLATS, A FLEXIBLE TAPE HAVING A SUBSTANTIALLY GREATER WIDTH THAN THICKNESS, A BODY SECURED TO SAID HEAD BAR ADJACENT ONE END THEREOF HAVING A SLOT WHICH IS SEMICIRCULAR ABOUT A VERTICAL AXIS AND OF A VERTICAL DEPTH TO ACCOMMODATE THE WIDTH OF SAID TAPE, SAID TAPE BEING TRAINED THROUGH SAID SLOT AND HAVING FIRST AND SECOND END PORTIONS ON OPPOSITE SIDES OF SAID SLOT WHICH EXTEND ALONG SAID HEAD BAR AND ARE ESSENTIALLY PARALLEL TO ITS LONGITUDINAL AXIS, A CONNECTION BETWEEN EACH OF SAID FIRST SIDE ELEMENTS AND SAID FIRST END PORTION OF THE TAPE AND BETWEEN EACH OF SAID SECOND SIDE ELEMENTS AND SAID SECOND END PORTION OF THE TAPE, A GUIDE FOR EACH SIDE ELEMENT INTERMEDIATE SAID CONNECTION AND SAID CROSS SUPPORTS AND SECURED TO SAID HEAD BAR, A CORD CONNECTED TO EACH OF SAID END PORTIONS OF SAID TAPE, A STOP FOR ENGAGEMENT WITH EACH END PORTION OF SAID TAPE TO LIMIT ITS LONGITUDINAL MOVEMENT, A CORD GUIDE ON EACH OF SAID STOPS, A MEMBER PIVOTED ON SAID HEAD BAR AROUND A SUBSTANTIALLY VERTICAL PIVOT ADJACENT THE END OF SAID BAR SPACED FROM SAID BODY, A VERTICAL FLANGE ON SAID MEMBER ADJACENT AN EDGE OF SAID HEAD BAR, AND A PLURALITY OF CORD GUIDES ON SAID FLANGE, SAID CORDS EXTENDING FROM SAID GUIDES ON SAID STOPS TO SAID GUIDES ON SAID FLANGE. 